1. Field of the Invention
The inventions relate to features improving performance of compound archery bows, namely:                (i) cable guards that separate the intersecting crossing locus of the inside cables, allowing the cables to freely glide through the guard as the bow is drawn and released.        (ii) a dual cam power pulley for a single-cam compound bow with two lobed cable races wherein the power cable winds and unwinds as the inside drawstring cable segment unwinds and winds around a common lobed cable race; and        (iii) mounting and limb-pod structures at the respective ends of the bow riser for anchoring, aligning and supporting extending bow limbs for flexure.        
2. Description of the Prior Art
Modern compound bows typically include a rigid central, structural riser typically composed of alloys of aluminum, magnesium, and/or titanium, and a pair of resilient bow-limbs variously, mounted, anchored, and aligned extending from the opposite ends of the riser.
Single-cam compound bows have a single, power-cam pulley or bow eccentric (power cam) mounted and supported for rotation typically at the distal end of the lower extending bow limb and an idler or control pulley mounted and supported for rotation typically at the distal end of the upper of the extending bow limb. A power cable with a yoke end presenting a pair of loops typically is anchored around extending axle ends of the idler/control pulley at the distal end of upper bow limb. The other end of the power cable is anchored and journaled for winding around a lobed cam cable race of the power cam as the bow is drawn. The drawstring cable of a single-cam bow typically loops around the idler/control pulley with each cable end anchored to, and journaled for unwinding from around two separate lobed cam cable races of the power cam as the bow is drawn and released for launching an arrow. In some instances the ends of drawstring cable are respectively anchored between the bow limbs with one end journaled for unwinding from around a lobed cable race of the power cam and the other end unwinding from around a lobed cable race of the idler/control pulley. Still other embodiments contemplate looping the drawstring cable around the idler/control pulley and anchoring the cable within the periphery of the cable race dividing the cable into a drawstring segment and a control string segment. [See U.S. Pat. No. 6,666,202, Darlington.] Typically the power cable and the control segment of the drawstring cable (the inside cables) cross ‘inside’ between the drawstring cable segment and the riser. The crossing inside cables can and do often rub against each other as the single-cam compound bow is drawn and released.
Dual-cam compound bows have power cams mounted and supported for rotation at the distal ends of both the upper and lower extending resilient limbs of the bow. Two power cables each have one end anchored and journaled for winding around a lobed race of one of the respective power cams. The power cables typically have a yoke end presenting a pair of looped ends for anchoring around extending axle ends of the power cam on the opposite bow limb. The respective ends of the drawstring cable that launches arrows from the bow are anchored and journaled for unwinding from around lobed drawstring cable races of the respective power cams winding the respective power cables up around the power cable races of the power cams as the bow is drawn. Other embodiments contemplate a binary cam arrangement where the respective power cables each have both ends respectively anchored for winding and unwinding from around lobed cable races of the respective power cams, where, each power cable winds up around one power cam and unwinds from around the other power cam on the opposite bow limb as the is drawstring cable is drawn. [See U.S. Pat. No. 7,305,979, Yehle.] Typically, the power cable and the return segment cables) cross ‘inside’ the drawstring cable segment between it and the riser. As with single cam bows, the crossing inside cables of dual-cam compound bows can and often do rub against each other as the bow is drawn and released.
In both single and dual-cam compound bows the lobed cam races of the power cam upon which the drawstring and power-string cables wind and unwind are configured to vary the force resisting the draw of the drawstring cable of the bow for launching an arrow with the objectives of lessening the force required as the drawstring cable approaches a maximum (peak) draw position, while preserving the stored or potential energy of the drawn bow, and to tailor acceleration of a nocked arrow upon release of the drawstring.
Design aspects that affect performance of compound bows include the mounts securing the bow limbs to the riser, flexure and alignment of the bow limbs relative to the riser and each other such that the drawstring cable and the centerline of the assembled bow share a common plane. Also the bow limbs, power-cams and idler/control pulleys all must be synchronized, tuned balanced and aligned with the objectives of assuring a nocked arrow is accelerated linearly by the drawn drawstring cable upon release. Ideally, the bow limbs should flex evenly without twisting both as the bow is drawn and upon release for driving an arrow. The cam races of the respective power cams of dual-cam bows and the power cam and idler/control pulley of single cam bows should not induce any variances in either the vertical or horizontal positions of the nock position of the arrow on the released drawstring cable it accelerates the arrow from the bow.
Compound bows also necessarily include a cable guard rod mounted on the bow riser extending backward parallel the bowstring plane typically with a translating cable slider that captures the inside, crossing cables and holds them laterally out from the plane of the drawstring cable segment away from fletching of launched arrows. Typically the respective crossing inside cables are captured and in separate variously configured channels milled into solid pieces of low friction, ultra-high-molecular-weight (UHMW) polymer such as POM (Delrin®) or PTFT (Teflon®). However, as compound bows are drawn and released, the locus of the crossing intersection of the inside cables translates both horizontally back and forth and vertically up and down as the bow limbs flex in and spring apart launching arrows. The body of existing cable sliders between the respective milled cable channels capturing the cross inside cables constrain (prevent) the locus of crossing intersection of the inside cables from moving through the sliders, i.e., constrain vertical translation of the crossing intersection of the inside cables to either above or below the horizontal plane of a guard rod on-which the cable slider slides. In fact, as illustrated in FIG. 4, the force of the higher tensioned inside cable on the slider can bind and/or deflect the cable of the lower tensioned inside cable, as the locus of the crossing intersection approaches the vertical position of the guard rod on which the cable slide slides as the bow is drawn and released.
Also the crossing inside cables of most compound bows will rub against each other as the bow is drawn and released. Skewing asymmetrical stresses attributable to cable guard rods with constraining slides, and frictional stresses of rubbing crossing of inside strings compromise compound bow performance.
Compound bow are classified by the MANUAL OF PATENT CLASSIFICATION published by U.S. Patent Office generally in U.S. Class 124, subclass 25.6 with various means affecting performance of the bows being further classified in subclasses 23 R, 24 R, 86, 88 & 900. In particular, patents in U.S. Class 124/86 & 88 relate to means for securing bow limbs to the ends of the riser. Patents in U.S. Class 124/900 generally relate to limb tip rotatable element structures e.g., the power cams, idler/control pulleys/wheels and the like that provide the mechanical advantage as the bow is drawn and released. The designated class specified by the International Patent Classification protocols for compound bows and their features is F41B 5/10.